Maintaining comfort and support for the sitting individual, particularly in the work environment, has been the goal of industrial health practitioners for years. One way of achieving this goal has been through the use of ergonomically designed chairs. These types of chairs attempt to support the individual such that pressure on the pelvic and lumbar regions of the body is reduced--which has been found to increase circulation, require less muscle activity, and generally provide other health benefits. While these types of chairs provide certain benefits in supporting the sitting individual which are typically not found in conventional chairs, ergonomically designed chairs can be relatively expensive, require replacement of chairs previously acquired, and can be limited in flexibility in adjusting to individuals with particular comfort and support requirements.
Another way of achieving proper comfort and support for the sitting individual has been through the use of cushions, and in particular, seat and/or back cushions. For example, back cushions can be attached to the back of the chair to provide a certain amount of comfort and support for the lumbar region of the individual; while seat cushions can be placed on the seat of a chair to provide comfort and support for both the lumbar and pelvic regions of the individual. The seat and back cushions can be relatively less expensive than ergonomically designed chairs, can be used with existing chairs, and in some cases allow a certain amount of adjustment to compensate for the particular comfort and support requirements of the individual.
Seat and back cushions of this type have been developed to correct posture or muscular imbalances, to provide support to compensate for a poorly-designed chair, and/or to provide a favorable physiological lumbar lordosis for the sitting individual. "Lumbar lordosis" is the slight forward curvature of the spine in the lumbar region achieved during forward tilt sitting. This position minimizes the pressure on the invertebral discs, requires less muscle activity (e.g., diaphragm function) than the Kyphotic ("hunched-over") posture, and minimizes stress on the posterior lumbar ligaments.
For example, one type of back cushion is shown in Feldman, U.S. Pat. No. 4,759,543; and Beier, U.S. Pat. No. 4,810,034. These references disclose orthopedic devices attached to or leaning against the back of the chair to support the lumbar region of the spine when a person is in a sitting position. These orthopedic devices have inflatable air chambers which can be inflated/deflated depending upon the desired lumbar support.
Another type of back cushion is shown in Bodeen, U.S. Pat. No. 3,974,827 ("Bodeen"). This reference discloses a cushion having a backrest and a lumbar support cushion enclosed within a cover. The lumbar support cushion can be adjusted relative to the backrest (or removed and replaced) to accommodate the physical structure of different individuals.
Still another type of back cushion is shown in Watson, U.S. Pat. No. 4,471,993 ("Watson"). The Watson device includes an orthopedic-shaped structural support formed of thermoplastic material and covered by a fabric enclosure. The Watson device includes straps which allow the cushion to be attached to the back of a chair or seat.
On the other hand, one type of seat cushion is shown in Hellwig, U.S. Pat. No. 4,592,589 and Frantz, U.S. Pat. No. 4,960,304. These references disclose a seat cushion having inflatable enclosures which can be inflated/deflated depending upon the necessary support for the pelvis and the lumbar region.
Although the aforementioned seat and back cushions provide a certain amount of flexibility in adjusting the profile of the cushion, there is a continued need for relatively inexpensive seat and-back cushions which can be simply and easily adjusted to provide a cushion which can be personalized to the particular comfort and support needs of the individual.